Reinforced cartons



United States Patent 3,235,163 REHNFORCED CARTGNS Russell J. Hennessey, St. Paul, Minn assignor to Waldorf Paper Products Company, St. Paul, Minn, a corporation of Minnesota Filed Mar. 23, 1964, Ser. No. 353,937 3 Claims. (Cl. 229-37) This invention relates to an improvement in reinforced cartons and deals particularly with a rectangular carton having two opposed parallel main panels connected intermediate their edges by a partition structure to prevent the outward bulging of the side walls.

In years past, paperboard cartons which were used for containing flour, powdered milk, and the like were made of relatively stiff and rigid board, and were usually overwrapped by means of a thin paper label. However, such cartons are relatively expensive and somewhat slow to overwrap and accordingly there has been a continuous trend toward forming these packages out of lighter weight paperboard in the interest of economy. The biggest difficulty with the use of lighter weight paperboard lies in the fact that the product tends to bulge the larger walls of the packages outwardly as the cartons are moved about. Various means have been provided for preventing this bulge, the most common means being the provision of a central partition or connecting strip connecting the parallel large walls of the carton to hold them from bulging. The present invention resides in a carton of this general type.

Patent 3,047,204 issued July 31, l962, to Richard S. Wolowicz discloses a reinforcing structure which is added as an extension of the glue flap connecting the walls in tubular relation. In the formation of this carton, the extension which forms the partition structure is folded back along its line of connection with the glue flap and a portion of the extension is adhered to one main panel. Then the carton is glued in the ordinary manner, a second portion of the extension being adhered to the other main panel. This extension includes an inner flap which is defined by a generally U-shaped out line, the inner flap including a partition wall and an anchoring flap portion. The edge or the outer fiap' is adhered to one of the main wall panels while the anchoring flange of the inner flap is adhered to the opposite main panel. As a result, the intermediate portion of the carton walls is restrained from bulging.

This construction has been, and is being, used successfully. However, there are certain objections to the construction. to the edge of the glue flap, and the glue flap is hinged to one of the wide or main panels of the carton so as to overlap the relatively narrow side wall panel. As the extension unit is adhered to the two main panels, and as the glue flap remains in the same plane as one of the main panels during the flap gluing operation, the extension must be long enough to fold back past the center of the main panel to which the glue flap is hinged. Furthermore, the structure results in a pair of connecting strips which must bend as the carton' is squared up. These connecting strips tend to interfere with the mandrels which are usually inserted into the carton during the process of sealing one end and for holding the carton square during this closing process.

I have found that by the simple expedient of changing the location of the glue flap, a much better and more economical construction will result. By securing the glue flap to one of the narrower side wall panels and by connecting the partition forming extension to this glue flap, it is possible to reduce the length of the partition extension by a distance equal to twice the width of the glue flap.

In the first place, the partition unit is hinged Patented Feb. 15 19th) Furthermore, as the extension lies flush against one of the main panels when it is squared up, there is nothing to interfere with the squaring up of the carton, and the partition may fit over a split mandrel during the process of sealing the first end of the carton if it is so desired.

It is an object of the present invention to provide a rectangular tubular carton having relatively Wide main panels and relatively narrow side panels, and in providing glue flap hingedly connected to one of the narrower side walls. A partition forming extension is provided on the glue flap which is of proper length to extend slightly beyond the center line of the adjoining main panel if the partition is to be in the middle of the carton. The center portion of this extension is out along a U-shap'ed cut line, the ends of which usually terminate at a point adjoining adjacent the center line of the main panel to which the extension is secured. The area defined by the U-shaped out line is divided by fold lines into a partition panel and an anchoring flange. During the closing of the carton, the main portion of the extension is adhered in face contact with one main panel while the anchoring flange is adhered to the other main panel. When the carton is squared up, a partition is formed to prevent the bulge of the lower portion of the c'arton.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

FIGURE 1 is a perspective view of a carton embodying the present invention, a portion of the carton being broken away to disclose the interior partition structure.

FIGURE 2 is a cross-sectional view on a horizontal plane through the structure shown in FIGURE 1, the position of the section being indicated by the line 2-2 of FIGURE 1.

FIGURE 3 is a diagrammatic view of the blank from which the carton is formed.

FIGURE 4 is a diagrammatic view of a ilat blank after the first folding operation.

FIGURE 5 is a diagrammatic view of the blank after the second folding operation.

The carton A is formed of the blank best illustrated in FIGURE 1 of the drawings. This blank includes a main panel 161*, aside wall panel ill, a second main panel 12, and a second side wall panel 13 foldably connected along parallel lines of fold M, 15, and 16. The main panels 1th and 12 are preferably more than twice the width of the end wall panels 13 in order that the partition may be locatedat thecenter of the main panels.

The wall panels described are usually connected along their upper edges by a substantially common line of fold 17 to top closure flaps i9, 29, 21, and 22 while the lower edges of the wall panels are connected along a fold line 23 to bottom closing flaps 24, 25, 2e, and 27. Obviously, other types of enclosures could be similarly used.

A glue help 29 is hingedly connected to the side wall 13 along a fold line 30. A partition wall extension is indicated in general by the numeral 31 and extends integrally from the glue iiap 29. Usually the vertical height of the extension 31 is substantially equal to one half the height f the wall panels iii, 11, i2, and 13 and has its lower edge 32 nearly aligned with the fold line 23 so as not to interfere with the formation of the lower closure by the closure liap as, 25, 26, and 27. The width of the extension 31 depends upon the proportion of the various wall panels, but it is preferred that the combined widths of the side wall 13 and glue flap 29 be somewhat less than the width W or bne halt" the main panels 10 and 12, or from the fold line 16 to the broken line 33 which indicates the center line of the panel 12. If this is not true, the partition cannot be located at the center of the main panels.

The extension 31 is preferably generally rectangular in outline. An inner flap structure 34 is formed in the extension 31 by a generally U-shapcd out line arrangement including a vertical out line 35 and a pair of horizontal out lines 36 and 37 extending from the ends of the cut line 35. The out line 35 is usually spaced from the fold line 30 a distance substantially equal to the width of the glue flap 29 so that the glue flap extends continuously throughout the height of the carton wall panels. The U-shaped cut lines thus define an inner flap structure 34 which is enclosed Within a rectangular frame, this frame including the lower portion of the glue flap 29, an upper horizontal strap 39, a lower horizontal strap 40, and a vertical strap 41 connecting the straps 39 and 40. The inner flap structure 34 is connected to the outer flap structure along a vertical fold line 42.

The inner panel structure 34 is divided by a vertical fold line 43 to provide a partition panel 44 hinged to the outer frame portion along the fold line 4-2, and an anchoring flange 45 which will later be secured to the panel 12. As it is usually desired that the partition panel 44 extend across the center portions of the cartons, the fold line 43 is preferably located to coincide with the center line 33 of the panel 12 when the blank is folded along the fold line 16. In other words, in the completed form of the carton, the anchoring flange 4-5 will overlie the area 4-6 indicated by broken lines in FIGURE 1 adjoining the center line 33. The partition panel 44 also must be of a width substantially equal to the width of the side walls 11 and 13. As indicated in FIGURE 1, the U-shaped cut lines which define the inner flap structure 34 may include diagonally extending end portions 47 which tend to eliminate any binding of the inner flap structure within the outer frame which has been described.

The carton A may be folded on a conventional straight line of glue equipped with spot gluing equipment. With the flat blank in the position illustrated in FIGURE 3, adhesive is applied either to the anchoring flange 45 or the area 46 of the main panel 12. The carton blank is then folded along the fold line 16, bringing the side wall 13, the glue flap 29, and the extension 31 into face contact with the main panel 12. After this first folding operation, the blank appears as indicated in FIGURE 4 of the drawings. To complete the operation, ahdesive is applied to the glue flap 2? as well as to a portion of the outer flap structure, usually along the strip 41 between the end edge of the extension and the fold line 42. In many instances, this adhesive is applied to the under surface of the blank while it is flat, as these adhesive surfaces need not be spot glued. The carton is completed by folding the blank along the fold line 14 to bring the main panel into overlying relation with the glue fiap 29 and the extension 31. The outer frame portion of the extension outwardly of the inner flap portion 34 is adhered in face contact with the wall panel 10, and the carton is glued in tubular relation along the glue flap.

In accordance with the patent statutes I have described the principles of construction and operation of my reinforced carton, and while I have endeavored to set forth the best embodiments thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A reinforced carton including:

a first main panel, a first side panel, a second main panel and a second side panel foldably connected along parallel fold lines,

a glue flap hinged to said second side wall panel, the combined width of the second side panel and glue flap being less than one half the width of said main panels,

a partition panel extension connected to said glue flap and extending in a direction away from the line of fold connecting said glue fiap to said second side wall,

an inner flap structure within said partition panel extension and hinged thereto along a line parallel to the said parallel fold lines,

said inner flap structure being defined by substantially continuous cut lines terminating at said line of fold connecting said inner flap structure to said extension and extending toward said glue flap in flat folded form of said blank,

said inner flap structure including a partition panel of a width substantially equal to said side panels, and an anchoring flange connected to the end of said partition panel along a line parallel to said previously described fold lines,

a portion of said extension outwardly of said inner flap structure, and said glue flap being adhered in face contact with the inner surface of said first main panel, and

said anchoring flange being adhered in face contact with the inner surface of said second main panel.

2. A reinforced carton including:

a first main panel, a first side panel, a second main panel and a second side panel connected along parallel fold lines,

a glue flap hinged to said second side Wall panel,

a partition panel extension connected to said glue flap and extending in a direction away from the line of fold connecting said glue flap to said second side wall,

a partition panel substantially enclosed within said partition panel extension and hingedly connected thereto along a fold line parallel to said previously described fold lines and extending in a direction toward said glue flap from said last named fold line in flat condition of the blank from which said carton is formed,

an anchoring flap hinged to said partition panel along a fold line parallel to said previously described fold lines and located between said partition panel and said glue flap in fiat condition of the blank,

said main panels being of substantially equal width and said side panels and partition panel being of substantially equal width,

said glue flap and partition panel extension being adhered in face contact with said first main panel and said anchoring flap being adhered in face contact with said second main panel.

3. The structure of claim 2 and in which the distance between the fold line connecting said glue flap to said second side panel and said fold line connecting said partition panel to said partition panel extension is equal to about one half the width of said main panels.

References Cited by the Examiner UNITED STATES PATENTS 2,807,404 9/1957 Cote 229-27 3,106,876 10/1963 Dewhurst 22927 3,135,453 6/1964 Struble 22927 3,168,211 2/1965 Potter 22928 JOSEPH R. LECLAIR, Primary Examiner.

I. F. MCNULTY, D. F. NORTON,

Assistant Examiners. 

1. A REINFORCED CARTON INCLUDING: A FIRST MAIN PANEL, A FIRST SIDE PANEL, A SECOND MAIN PANEL AND A SECOND SIDE PANEL FOLDABLY CONNECTED ALONG PARALLEL FOLD LINES, A GLUE FLAP HINGED TO SAID SECOND SIDE WALL PANEL, THE COMBINED WIDTH OF THE SECOND SIDE PANEL AND GLUE FLAP BEING LESS THAN ONE HALF THE WIDTH OF SAID MAIN PANELS, A PARTITION PANEL EXTENSION CONNECTED TO SAID GLUE FLAP AND EXTENDING IN A DIRECTION AWAY FROM THE LINE OF FOLD CONNECTING SAID GLUE FLAP TO SAID SECOND SIDE WALL, AN INNER FLAP STRUCTURE WITHIN SAID PARTITION PANEL EXTENSION AND HINGED THERETO ALONG A LINE PARALLEL TO THE SAID PARALLEL FOLD LINES, SAID INNER FLAP STRUCTURE BEING DEFINED BY SUBSTANTIALLY CONTINUOUS CUT LINES TERMINATING AT SAID LINE OF FOLD CONNECTING SAID INNER FLAP STRUCTURE TO SAID EXTENSION AND EXTENDING TOWARD SAID GLUE FLAP IN FLAT FOLDED FORM OF SAID BLANK, SAID INNER FLAT STRUCTURE INCLUDING A PARTITION PANEL OF A WIDTH SUBSTANTIALLY EQUAL TO SAID SIDE PANELS, AND AN ANCHORING FLANGE CONNECTED TO THE END OF SAID PARTITION PANEL ALONG A LINE PARALLEL TO SAID PREVIOUSLY DESCRIBED FOLD LINES, A PORTION OF SAID EXTENSION OUTWARDLY OF SAID INNER FLAP STRUCTURE, AND SAID GLUE FLAP BEING ADHERED IN FACE CONTACT WITH THE INNER SURFACE OF SAID FIRST MAIN PANEL, AND SAID ANCHORING FLANGE BEING ADHERED IN FACE CONTACT WITH THE INNER SURFACE OF SAID SECOND MAIN PANEL. 